lavc: introduce VideoDSPContext

Move some functions from dsputil. The idea is that videodsp contains
functions that are useful for a large and varied set of video decoders.
Currently, it contains emulated_edge_mc() and prefetch().

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

1 files changed, 119 insertions, 0 deletions

diff --git a/libavcodec/x86/videodsp_init.c b/libavcodec/x86/videodsp_init.c
new file mode 100644
index 0000000000..07a0324c69
--- /dev/null
+++ b/libavcodec/x86/videodsp_init.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2012 Ronald S. Bultje
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/common.h"
+#include "libavutil/cpu.h"
+#include "libavutil/mem.h"
+#include "libavutil/x86/asm.h"
+#include "libavcodec/videodsp.h"
+
+#if HAVE_YASM
+typedef void emu_edge_core_func(uint8_t *buf, const uint8_t *src,
+                                x86_reg linesize, x86_reg start_y,
+                                x86_reg end_y, x86_reg block_h,
+                                x86_reg start_x, x86_reg end_x,
+                                x86_reg block_w);
+extern emu_edge_core_func ff_emu_edge_core_mmx;
+extern emu_edge_core_func ff_emu_edge_core_sse;
+
+static av_always_inline void emulated_edge_mc(uint8_t *buf, const uint8_t *src,
+                                              ptrdiff_t linesize,
+                                              int block_w, int block_h,
+                                              int src_x, int src_y,
+                                              int w, int h,
+                                              emu_edge_core_func *core_fn)
+{
+    int start_y, start_x, end_y, end_x, src_y_add = 0;
+
+    if (src_y >= h) {
+        src_y_add = h - 1 - src_y;
+        src_y     = h - 1;
+    } else if (src_y <= -block_h) {
+        src_y_add = 1 - block_h - src_y;
+        src_y     = 1 - block_h;
+    }
+    if (src_x >= w) {
+        src   += w - 1 - src_x;
+        src_x  = w - 1;
+    } else if (src_x <= -block_w) {
+        src   += 1 - block_w - src_x;
+        src_x  = 1 - block_w;
+    }
+
+    start_y = FFMAX(0, -src_y);
+    start_x = FFMAX(0, -src_x);
+    end_y   = FFMIN(block_h, h-src_y);
+    end_x   = FFMIN(block_w, w-src_x);
+    assert(start_x < end_x && block_w > 0);
+    assert(start_y < end_y && block_h > 0);
+
+    // fill in the to-be-copied part plus all above/below
+    src += (src_y_add + start_y) * linesize + start_x;
+    buf += start_x;
+    core_fn(buf, src, linesize, start_y, end_y,
+            block_h, start_x, end_x, block_w);
+}
+
+#if ARCH_X86_32
+static av_noinline void emulated_edge_mc_mmx(uint8_t *buf, const uint8_t *src,
+                                             ptrdiff_t linesize,
+                                             int block_w, int block_h,
+                                             int src_x, int src_y, int w, int h)
+{
+    emulated_edge_mc(buf, src, linesize, block_w, block_h, src_x, src_y,
+                     w, h, &ff_emu_edge_core_mmx);
+}
+#endif
+
+static av_noinline void emulated_edge_mc_sse(uint8_t *buf, const uint8_t *src,
+                                             ptrdiff_t linesize,
+                                             int block_w, int block_h,
+                                             int src_x, int src_y, int w, int h)
+{
+    emulated_edge_mc(buf, src, linesize, block_w, block_h, src_x, src_y,
+                     w, h, &ff_emu_edge_core_sse);
+}
+#endif /* HAVE_YASM */
+
+void ff_prefetch_mmxext(uint8_t *buf, ptrdiff_t stride, int h);
+void ff_prefetch_3dnow(uint8_t *buf, ptrdiff_t stride, int h);
+
+void ff_videodsp_init_x86(VideoDSPContext *ctx, int bpc)
+{
+#if HAVE_YASM
+    int mm_flags = av_get_cpu_flags();
+
+#if ARCH_X86_32
+    if (bpc <= 8 && mm_flags & AV_CPU_FLAG_MMX) {
+        ctx->emulated_edge_mc = emulated_edge_mc_mmx;
+    }
+    if (mm_flags & AV_CPU_FLAG_3DNOW) {
+        ctx->prefetch = ff_prefetch_3dnow;
+    }
+#endif /* ARCH_X86_32 */
+    if (mm_flags & AV_CPU_FLAG_MMXEXT) {
+        ctx->prefetch = ff_prefetch_mmxext;
+    }
+    if (bpc <= 8 && mm_flags & AV_CPU_FLAG_SSE) {
+        ctx->emulated_edge_mc = emulated_edge_mc_sse;
+    }
+#endif /* HAVE_YASM */
+}